A 20-year-old Winslow man was arrested Tuesday afternoon after selling marijuana to agents of the Fairfield Police Department — twice.

Police Chief Thomas Gould wouldn’t say whether it was an undercover police officer or a cooperating witness who made the purchases, but it led to officers executing a search warrant on Dennis Brassard’s 1997 Saturn about 2 p.m. on Newhall Street in Fairfield.

“We made two controlled purchases of marijuana from the suspect,” Gould said.

During the search, Gould said, officers Ryan Johnson and Jordan Brooks confiscated about a half-ounce of marijuana from Brassard.

Gould said the investigation was begun after the department heard reports that Brassard was selling drugs in Mill Island Park.

Brassard has been charged with two counts of aggravated trafficking of schedule Z drugs, each a class C crime punishable by up to five years in prison and a $5,000 fine. Because the sales are alleged to have taken place in Mill Island Park, a drug-free safe zone, the charges were elevated to aggravated.

He also was charged with possession of marijuana, a class E crime punishable by up to six months in prison and a $1,000 fine.

A search of arrest reports shows no other criminal history for Brassard, who graduated from Lawrence High School in 2013 after having made high honors every year since 2011, when he was a sophomore.

He works for the school as a bus monitor and custodian and for a local Subway, according to his Facebook page.

Attempts to contact Brassard were unsuccessful. He was released on $500 cash bail and is scheduled to appear May 14 in Skowhegan Superior Court.

In 2012, the most recent year on record, state statistics show that there were 467 arrests on charges of sale or manufacturing of marijuana.

Of that total, 127 involved people aged 20 or younger.

That year, there were 2,734 arrests on charges of possession of marijuana, including 1,136 involving people aged 20 or younger.

Matt Hongoltz-Hetling — 861-9287 mhhetling@centralmaine.com Twitter: @hh_matt